Do we unfairly demonise food processing?

Molecules, Microbes, and Meals: The Surprising Science of Food

Today, we constantly hear concerns about the dangers of processed food and it is sometimes portrayed as opposite to natural and healthy food. Is this warranted? What does food processing even really mean?

To a food scientist, food processing is any method used to make food safe to eat, enhance its stability, or change its form. Humans are the only species that processes its food, rather than eating plants or animals in the form in which they are found in nature. Learning to cook food was a key step in human evolution, as this made food far more digestible, and freed up energy and metabolic activity to allow development of higher intelligence and all that followed.

Later, rudimentary food processing that allowed food to be stabilised and transported is proposed to have been a key step in the establishment of civilisations and cities, allowing people to become less dependent on finding and producing food. This allowed for the diversification of roles in society beyond primary producers and hunter-gatherers.

Early human migrations also depended on groups being able to transport food. Indeed, the discovery of cheese is attributed by legend to the use of containers made from calf stomachs, from which was extracted an enzyme called chymosin which converted milk therein to a mixture of curds formed from enzymatically destabilised milk protein and surrounding fluid whey. Later migrations in the form of great voyages of exploration required food to be preserved by means such as pickling and salting, while the need for Napoleon to feed his armies on their campaigns led him to offer prizes for solution to this problem, one of which was won by Nicholas Appert for the discovery of what became canning. Most recently, many developments in food safety and packaging which have become commonplace were spurred by the very specific needs of NASA for ultra-safe food for space travel, in easy to open pouches, which were resistant to spills and didn’t produce crumbs in zero-gravity.

So, food processing has been with civilisation for as long as we have had civilisation, and key processes such as heating, drying, fermentation, and refrigeration have been practiced long before the science underpinning how these affect food characteristics. If we did not have food processing, consumers would not have access to safe food, to a variety of food from different places, or to food which was stable enough to reduce the number of trips needed to markets to replace it.

If we did not have food processing, consumers would not have access to safe food, to a variety of food from different places, or to food which was stable enough to reduce the number of trips needed to markets to replace it.

Nonetheless, the concept of food processing, the steps such as heating or drying taken to make food safe and stable, is often mixed up with discussions about processed food, with implications of nutritional inferiority and high levels of unhealthy components like salt and sugar. Processing is seen as being something that is used to make food less fresh, less natural, and so more suspicious. Nonetheless, even though we say we don’t want processed food, every food product, before it gets to your mouth, has been subjected to some form of processing and treatment that has a scientific basis, be it as simple as washing or chilling. It could be argued that life would be even more nasty, brutish and short if it were not for food processing, as the primary goal of food processing, and the primary responsibility of those handling and preparing food, in any context, is to ensure that food is safe to consume.

The modern perception of food processing thus intertwines concepts of physical processes (like severe heat treatment) and chemical formulation of food. Nonetheless, while consumers express concern about the presence of chemical preservatives in their food, many products which have been with us for a long time include salt, sugar, acid and even alcohol specifically because they are powerful chemical preservatives.

Consider the following list: Fluorene, Phenanthrene, Anthracene, Fluoranthene, Pyrene, Benzo(a)anthracene, Cyclopenta pyrene, Chrysene, Benzo(b) fuoranthene, Benzo(a)pyrene, and Benzo(g,h,i)perylene. Are these all nasty chemical products? No – these are just molecules that can be found in smoked salmon, according to a scientific study that characterised them. Consumer perception of food can be changed by identifying an ingredient by either its common name or its function. Compare emulsifier and egg, thickener and starch, or humectant and honey; in each case, the first functional term is more likely to be viewed suspiciously on a food label than the name of an ingredient which serves that function.

For thousands of years, we have added chemicals to food, like sugar to jam or salt to meat, or else exploited microbial processes that produced them in the food, like fermentation to produce acid or alcohol. In every such case, the reason these have persisted is because of the power of their chemical preservative effects.

Of course, past generations might have over-relied on such agents to preserve food, leading to formulations which, if consumed to excess, deliver excessive levels of components which can be less nutritionally desirable. However, modern food and nutritional science have greatly deepened our understanding of how food can best be preserved with the least impact on the food’s characteristics (an approach known as minimal processing) and ultimately yield the best nutritional formulation.

Overall, today, the science of food is much less appreciated in comparison to the social, artistic and cultural aspects of food. However, understanding the science behind what we eat can broaden our appreciation of it, and perhaps change our conceptions about the reasons why food is processed and formulated the way it is, and what that really means.

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